Vacuum thread trimmer

ABSTRACT

A vacuum thread trimmer in which a hollow shafted electric motor drives a rotating cutter tube inside a stationary cutter tube with the hollow shaft of the motor communicating with a vacuum pump at one end and with the hollow rotating cutter tube at the other end so that threads to be trimmed are drawn by vacuum up into the rotating cutter tube cut free by the rotation of the cutter tube with respect to the stationary cutter tube and moved on to a collection point.

United'States Patent 11113,602,172

[72] Inventor Murel B. Bray [56] References Cited 3108 Alameda AWL, El P850, Tex. 79905 UNITED STATES PATENTS P 2,722,728 11/1955 Stout 112/010. 1 [22] (A1969 2,989,935 6/1961 Butler 112/252 [45] 3,149,594 9/1964 Buckreus et al. 1 12/252 Primary ExaminerJames R. Boler AttorneyVi'ctor J. Evans & Co.

ABSTRACT: A vacuum thread trimmer in which a hollow shafted electric motor drives a rotating cutter tube inside a [54] VACUUM THREAD TRIMMER 3 Claims 12 Drawing stationary cutter tube with the hollow shaft of the motor com- [52] US. Cl 112/252, municating with a vacuum pump at one end and with the holl l2/DIG. l low rotating cutter tube at the other end so that threads to be [51] Int. Cl. D05b 65/06 trimmed are drawn by vacuum up into the rotating cutter tube [50] Field of Search 1 12/252, cut free by the rotation of the cutter tube with respect to the 129, 130, DIG. l; 26/ l 1 stationary cutter tube and moved on to a collection point.

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" vacuum thread trimmer so asto'be "'The" present irivention r thread I stitc U v, lately follo operation so'th'atall of the seams ws; stitching mmed er BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of the invention shown attached to a commercial sewing machine partially broken away and in section for convenience of illustration;

FIG. 2 is a fragmentary vertical sectional view taken along the line 22 of FIG. 1 looking in the direction of the arrows;

FIG. 3 isan inverted transverse sectional view taken along the line 33 of FIG. 1 looking in the direction of the arrows and partially broken away for convenience of illustration;

FIG. 4 is an enlarged fragmentary longitudinal sectional view taken along the line 4-4 of FIG. 1 looking in the directionof the arrows;

FIG. 5 is a front elevation of the guard foot; FIG. 6 is a side elevation of the guard foot;

FIG. 7 is a rear elevation of the guard foot;

FIG. 8 is a side elevation of the stationary cutter tube;

FIG. 9 is a vertical sectional view taken along the line 9-9 of FIG. 8 looking in the direction of the arrows;

FIG. 10 is a rear elevation of the guard foot; y

FIG. 11 is a side elevation of the rotating cutting tube; and

FIG. 12 is a bottom plan view of the stationary cutter and rotating cuttertubes in assembled position.

DESCRIPTION OF THE PREFERRED EMBODIMENT I Referring now to the drawings in detail wherein like reference characters indicate like parts throughout the several I FIGS. the reference numeral indicates generally a vacuum thread trimmer constructed in accordance with the invention.

The vacuum thread trimmer 20 serves as an attachment for a conventional commercial sewing machine indicated generally at 21. The sewing machine 21 includes a table surface 22 to which is attached a head 23. The head 23 carries a pressure foot 24 and conventional sewing apparatus indicated generally at 25.

An upright post 26 is positioned to overlie the head 23 and has a baseplate 27 secured to the lower end thereof. The 27 is secured to the head 23 by a pair of cap screws 28. A coupling 29 is vertically adjustably mounted on the post 26 and is fixed thereon by a pair of setscrews 30. A horizontal bar 31 is adjustably mounted in the coupling 29 and is fixed therein by a pair of setscrews 32. A bracket generally indicated at 33 is releasably secured to the outer end of the bar 31 by a bolt 34. The bracket 33 includes a generally rectangular upright flat plate 35 having a generally rectangular downwardly sloping flat plate 36 integrally secured thereto. An electric motor 38 is positioned with its hollow shaft 39 perpendicular to the plate 37. The motor 38 is secured to the plate 37 by a pair of bolts 40.

j t etdl ,PP v the hollow shaft 39. yoke fba r rimm 1 tachrnent'forcommereialse ng machines, of the..type in) 'which-looselthreads em H must be i removed. Th'e'attach I coilislprings 4 2 pair of boltsgll are secured to thetplate 37 arid-extend mounted the bans 41' and secured th beingsewnpasssunder-the untedin the bushing 45 in surrounding relation to the rotating cutter-tube 48 and hasa cbnic'a lly inw'ardly tapered lower end portion 51 provided with a pair of cutting teeth 52 to cooperate with the cutting teeth 49. The cutting tube and the yoke 42 float on the bolts 41 under pressure of the compression springs 43 so that the teeth 52 are held in engagement with the outer circumferences of the teeth 49 so as to maintain the sharpness of the teeth as wear occurs. The internal diameter of the tubular cutter 50 is undercut at 53 to provide a grease packing cavity between the tubular cutter 48 and the tubular cutter 50 as can be clearly seen in FIG. 4. A generally tubular foot guard 55 is mounted on the lower end of the tubular cutter 50 and is secured thereto by a setscrew 56. The foot guard 55 has an angularly extending foot 57 integrally formed on the lower end thereof and arranged to extend forwardly-parallel to the table surface 22 toward the pressure foot 24. The foot 57 is spaced above the table surface 22 to permit the cloth to slide easily under it from the machine pressure foot 24.

A vacuum housing 58 is mounted on the upper end of the motor 38 in communication with the hollow shaft 39 and a flexible vacuum tube 59 communicates with the vacuum housing 58 and extends to a vacuum pump (not shown).

A control box 60 is mounted on the panel 35 and has a switch 61 forming a part thereof for energizing and deenergizing the motor 38 as desired. i

In the use and operation of the invention the vacuum pump is set into motion to provide'vacuum in the cutter tube 48 and the motor 38 is rotated so that the cutter tube 48 rotates with respect to the cutter tube 50. Sewing is then done conventionally with-the commercial sewing machine 21 with the cloth passing under the pressure foot 24 and then under the guard foot 57 so as to come under the cutter tube 48 and the cutter tube 50. Loose threads remaining from the sewing process are sucked up into the cutter tube 48 by the vacuum'therein and the cutter teeth 49 cooperating with the cutter teeth 52 sever these threads so that they can be moved by the vacuum to a collection point.

Having thus described the preferred embodiment of the invention it should be understood that numerous structural modifications and adaptations may be resorted to without departing from the spirit of the invention.

What is claimed is:

1. A thread trimmer attachment in combination with a sewing machine of the type which includes a head having a sewing mechanism associated therewith comprising a rotatable hollow cutter, cutting teeth formed on the lower end of said cutter, a stationary cutter tube surrounding and rotatable cutter and having cutting teeth formed on the lower end thereof for cooperation with the cutter teeth on said rotatable cutter, means supporting said stationary cutter tube adjacent to and rearwardly of the sewing mechanism on said head, means for rotating said rotatable cutter, and means for applying a vacuum to said rotatable cutter to draw loose threads into said rotatable cutter to be severed by the cooperating cutter blades, the means for mounting said stationary cutter blade including means for resiliently urging said stationary cutter blade axially of said'rotatable cutter to maintain the cooperating cutting teeth in frictional contact.

2. A thread trimmer attachment in combination with a sewing machine of the type which includes a head having a into said rotatable cutter to be severed by the cooperating cutter blades, the means for rotating said rotatable cutter including a hollow shaft motor and the means for applying vacuum to said hollow rotatable cutter being connected to said hollow shaft.

3. A thread trimmer attachment in combination with a sewing machine of the type which includes a head having a sewing mechanism associated therewith comprising a rotatable hollow cutter, cutting teeth formed on the lower end of said cutter, a stationary cutter tube surrounding said rotatable cutter and having cutting teeth formed 0 n the lower end thereof for cooperation with the cutter teeth on said rotatable cutter, means supporting said stationary cutter tube adjacent to and rearwardly of the sewingmechanism on said head, means for rotating said rotatable cutter, and means for applying a vacuum to said rotatable cutter to draw loose threads into said rotatable cutter to be severed by the cooperating cutter blades, the cutting teeth on said rotatable cutter lying in a conical form and the cutting teeth on said stationary cutter lying in a cooperating conical form. 

1. A thread trimmer attachment in combination with a sewing machine of the type which includes a head having a sewing mechanism associated therewith comprising a rotatable hollow cutter, cutting teeth formed on the lower end of said cutter, a stationary Cutter tube surrounding and rotatable cutter and having cutting teeth formed on the lower end thereof for cooperation with the cutter teeth on said rotatable cutter, means supporting said stationary cutter tube adjacent to and rearwardly of the sewing mechanism on said head, means for rotating said rotatable cutter, and means for applying a vacuum to said rotatable cutter to draw loose threads into said rotatable cutter to be severed by the cooperating cutter blades, the means for mounting said stationary cutter blade including means for resiliently urging said stationary cutter blade axially of said rotatable cutter to maintain the cooperating cutting teeth in frictional contact.
 2. A thread trimmer attachment in combination with a sewing machine of the type which includes a head having a mechanism associated therewith comprising a rotatable hollow cutter, cutting teeth formed on the lower end of said cutter, a stationary cutter tube surrounding said rotatable cutter and having cutting teeth formed on the lower end thereof for cooperation with the cutter teeth on said rotatable cutter, means supporting said stationary cutter tube adjacent to and rearwardly of the sewing mechanism on said head, means for rotating said rotatable cutter, and means for applying a vacuum to said rotatable cutter to draw loose threads into said rotatable cutter to be severed by the cooperating cutter blades, the means for rotating said rotatable cutter including a hollow shaft motor and the means for applying vacuum to said hollow rotatable cutter being connected to said hollow shaft.
 3. A thread trimmer attachment in combination with a sewing machine of the type which includes a head having a sewing mechanism associated therewith comprising a rotatable hollow cutter, cutting teeth formed on the lower end of said cutter, a stationary cutter tube surrounding said rotatable cutter and having cutting teeth formed o n the lower end thereof for cooperation with the cutter teeth on said rotatable cutter, means supporting said stationary cutter tube adjacent to and rearwardly of the sewing mechanism on said head, means for rotating said rotatable cutter, and means for applying a vacuum to said rotatable cutter to draw loose threads into said rotatable cutter to be severed by the cooperating cutter blades, the cutting teeth on said rotatable cutter lying in a conical form and the cutting teeth on said stationary cutter lying in a cooperating conical form. 